Without limiting the scope of the invention, its background is described in connection with wastewater treatment.
Wastewaters generated from industrial activity contain a variety of potentially toxic and environmentally harmful compounds. These compounds present an increasingly serious threat to human and environmental health (Tiwari et al., 2013). Organic dyes are aromatic compounds that are commonly used in various fields of industry, such as textile, pulp and paper, printing, food, plastic, tanneries, etc. (Moussavi and Mahmoudi, 2009a). Because of their high solubility in water, they can easily be transported within the aqueous environment, and may pose many serious ecological, environmental, and health hazards (Moussavi and Mahmoudi, 2009b). Various conventional methods, including physical, chemical, and biological technologies have been proposed for the removal of dyes from wastewater (Hamadanian et al., 2013, 2011; Robinson et al., 2001; van der Zee and Villaverde, 2005). Among the various removal technologies, adsorption is the most commonly used method due to its low cost, simple operation and design requirements, not being influenced by toxic substances and low residual product generation (Rafatullah et al., 2010; Tiwari et al., 2013). Recently, nanomaterials as —new adsorbents— have been investigated for the removal of various pollutions from water and wastewater, such as dyes, heavy metals, antibiotics, microbial pollutants, arsenic, pharmaceuticals, and phenolic compounds (Qu et al., 2013; Tayyebi et al., 2015a; Wang et al., 2013). Compared to more traditional adsorbents, the unique chemical and physical characteristics of the nanomaterials thus provide enhanced removal efficiencies for such contaminants.
U.S. Pat. No. 9,156,021, by Salam, et al., is entitled, “Method and nanocomposite for treating wastewater”, and is said to teach a method and nanocomposite for treating wastewater by treating aniline-containing wastewater with a magnetic nanocomposite. Nickel nitrate, iron nitrate and citric acid were dissolved in deionized water to form a metal nitrate and citric acid solution, which was then pH balanced. The pH balanced solution was then heated to form a gel, which is then ignited to form powdered NiFe2O4, and the nanoparticles were mixed with multi-walled carbon nanotubes to form a magnetic nanocomposite, such that the magnetic nanocomposite includes approximately 75 wt % of the multi-walled carbon nanotubes and approximately 25 wt % of the NiFe2O4. The magnetic nanocomposite was mixed into a volume of aniline-containing wastewater for adsorption and a magnetic field was applied to magnetically separate the magnetic nanocomposite and the adsorbed aniline from the wastewater.
U.S. Patent Application No. 20150183189, filed by Kim, et al., entitled “Graphene Hydrogel, Graphene Hydrogel Nanocomposite Materials, and Preparation Method Thereof”, is said to teach a graphene hydrogel, graphene hydrogel nanocomposite materials, and a preparation method thereof, wherein the graphene hydrogel includes pores between laminated graphene sheets, and the pores contain moisture. In addition, the graphene hydrogel nanocomposite material is said to include nanoparticles and porous pores between laminated graphene sheets, and the pores contain water.
U.S. Patent Application No. 20130098833, filed by Sun, et al., entitled “Method of preparing a nanocomposite membrane and nanocomposite membranes prepared thereof” is said to teach a method of preparing a nanocomposite membrane, comprising: (a) providing a nanocomposite solution comprising a polymer solution and nanomaterials; (b) subjecting the nanocomposite solution to a cold water bath to produce the nanocomposite membrane in a gel-like form; and (c) subjecting the gel nanocomposite membrane to a heat treatment to solidify the nanocomposite membrane, wherein the nanomaterials are dispersed within the polymer matrix of the nanocomposite membrane.